title: Cobalt-catalyzed C-H bond functionalizations with aryl and alkyl chlorides.
abstract: Inexpensive cobalt catalysts derived from N-heterocylic carbenes (NHC) allowed efficient catalytic C-H bond arylations on heteroaryl-substituted arenes with widely available aryl chlorides, which set the stage for the preparation of sterically hindered tri-ortho-substituted biaryls. Likewise, challenging direct alkylations with β-hydrogen-containing primary and even secondary alkyl chlorides proceeded on pyridyl- and pyrimidyl-substituted arenes and heteroarenes. The cobalt-catalyzed C-H bond functionalizations occurred efficiently at ambient reaction temperature with excellent levels of site-selectivities and ample scope. Mechanistic studies highlighted that electron-deficient aryl chlorides reacted preferentially, while the arenes kinetic C-H bond acidity was found to largely govern their reactivity.
authors.affiliation: Institut für Organische und Biomolekulare Chemie, Georg-August-Universität, Tammannstrasse 2, 37077 Göttingen, Germany.
authors.forename: Benudhar
authors.initials: B
authors.lastname: Punji
authors.forename: Weifeng
authors.initials: W
authors.lastname: Song
authors.forename: Grigory A
authors.initials: GA
authors.lastname: Shevchenko
authors.forename: Lutz
authors.initials: L
authors.lastname: Ackermann
mesh_terms: D000478:Alkylation; D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D002712:Chlorides / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D007211:Indoles / Q000737:chemistry; D008697:Methane / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: D002712:Chlorides; D006571:Heterocyclic Compounds; D007211:Indoles; C030011:carbene; D003035:Cobalt; D002244:Carbon; D006859:Hydrogen; C030374:indole; D008697:Methane
keywords: CH activation; alkylation; arylation; catalysis; cobalt